Strength Study of Concrete Made with Various Local Sands in Benin City, Nigeria

The paper focuses on the effect which varying the type of sand used in concrete will have on the compressive strength of concrete and seeks to determine the suitability of each sand for use in concrete works. The sand samples used include Okhoro, Ikpoba, Ovia and Okhuahiaerosion sands and Ikpoba, Ovia and Okhuahia river sands. Particle size distribution of the sands was first determined and the result was used to design grades 20, 25, and 30 concretes to Department of Environment (DOE) mix design method. Twelve cubes were cast from one particular sand sample and three cubes were tested at 7, 14 and 28 days for each grade of concrete respectively .The result revealed that the sand samples that are well graded gave the highest compressive strength; while the poorly graded sands gave lower strengths. Okhuahia river sand gave the strongest concrete followed by Ikpoba, and Ovia river sands, Okhuahia, Ikpoba, Ovia and Okhoro erosion sands. Particle size distribution within a sand zone probably did not affect strength but the impurity content did. However, the inter-zonal differences in particle sizes probably did affect strength. The result also showed that only the river sands and Okhuahia erosion sand are good for concrete making.